Mechanisms of Mono-Vacancy and Oxygen Permeability in Y2SiO5 Orthosilicate Studied by First-Principles Calculations

摘要

Understanding the mechanisms of native point defects and oxygeu-vacaney diffusion in Y2SiO5 is important to evaluate its performance as environmental and thermal barrier coating (ETBC).In the present first-principles calculations,we show that oxygen vacancy is the predominant vacancy species and prefers to form on the oxygen lattice sites inside SiO4 tetrahedra instead of on the interstitial non-silieon-bonded oxygen site.